Inhibition of melanogenesis in B16-F1 melanoma cells after exposure to diflubenzuron.

The insect growth regulator diflubenzuron was found to be a potent inhibitor of melanosome synthesis and release in mouse melanoma cell cultures, and after three to five successive passages of melanoma cells in growth medium containing this compound, these cells were unable to produce monolayers in untreated medium and were incapable of inducing tumor formation in mice. This is the first time that an insect growth regulator has been shown to have a deleterious effect on malignant cells of animals.